J. Phys. IV France 7 (1997) C2-1127-C2-1128
N- and Al-K-Edge EXAFS of AIN Grown on GaAs by MBEM. Katsikini1, 2, E.C. Paloura2, 3, E. Holub-Krappe2, T.S. Cheng4 and C.T. Foxon4
1 Aristotle University of Thessaloniki, Department of Physics, 54006 Thessaloniki, Greece
2 Hahn-Meitner Institute (A.S.), Glienicker Str. 100, 14109 Berlin, Germany
3 Aristotle University of Thessaloniki, Department of Physics 54006 Thessaloniki, Greece
4 University of Nottingham, Department of Physics, NG7 2RD UK
Hexagonal AIN, epitaxially grown on GaAs, is studied with X-ray absorption measurements at the N-and Al-K-edges. The measured nearest neighbour (nn) distances are found shorter than expected by 0.04Å to 0.13Å for the 1st to 3rd nn shells, respectively, while there is no evidence of undercoordination for the N or Al atoms. The reduction in the nn distances is attributed to the presence of oxygen contamination. The characteristic angular dependence of the N-K-edge NEXAFS spectra verifies the hexagonal structure of the AIN film while the N-AI-N bond angle, determined from the angular dependence of the NEXAFS spectra, is found equal to 53.8±5.7° indicating that the oxygen does not distort significantly the local symmetry around the N atom.
© EDP Sciences 1997